A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems. It generally includes redundant or backup power supplies, redundant data communications connections, environmental controls (e.g., air conditioning, fire suppression) and various security devices. Large data centers are industrial scale operations using as much electricity as a small town.
Data centers have their roots in the huge computer rooms of the early years of the computing industry. Early computer systems, complex to operate and maintain, required a special environment in which to operate. Many cables were necessary to connect all the components and methods to accommodate and organize these were devised, such as standard racks to mount equipment, raised floors, and cable trays (installed overhead or under the elevated floor). A single mainframe required a great deal of power, and had to be cooled to avoid overheating.
One of the components within data centers is the storage used by the computing systems. One approach is to store data on a multitude of computer systems, such that they behave as one storage system although data is distributed between them. These are called distributed storage systems.